Washing machine and method for controlling the same

Abstract

A washing machine may include a drum rotationally arranged for containing laundry, a motion detector configured to detect a motion of the laundry, and a controller configured to control rotation speed of the drum based on the detected motion such that the laundry shows a predetermined motion.

The invention claimed is: 
     
       1. A washing machine comprising:
 a cabinet on which an opening is formed; 
 a door arranged to close the opening; 
 a drum rotationally arranged in the cabinet to contain laundry; 
 a motion detector comprising a laundry detection sensor installed in an upper part of the door, where the laundry detection sensor is configured to output a signal corresponding to a motion of the laundry in the drum; and 
 a controller configured to control rotation speed of the drum such that the laundry moves in a predetermined motion, based on the signal. 
 
     
     
       2. The washing machine of  claim 1 , wherein the laundry detection sensor is installed in the upper part of the door and is offset from a vertical center line of the door. 
     
     
       3. The washing machine of  claim 2 , wherein the laundry detection sensor is configured to emit at least one of infrared rays, laser, radio waves, ultrasounds, and acoustic waves to the inside of the drum, and receive at least one of infrared rays, laser, radio waves, ultrasounds, and acoustic waves reflected from the laundry, and the controller is configured to determine a motion of the laundry based on at least one of infrared rays, laser, radio waves, ultrasounds, and acoustic waves received by the laundry detection sensor. 
     
     
       4. The washing machine of  claim 3 , wherein the controller is configured to control rotation speed of the drum based on detection time for which the laundry detection sensor receives at least one of the reflected infrared rays, laser, radio waves, ultrasounds, and acoustic waves. 
     
     
       5. The washing machine of  claim 1 , wherein the motion detector further comprises another laundry detection sensor installed in approximately the center of the door, and the other laundry detection sensor is configured to output another signal corresponding to a motion of the laundry in the drum, and
 wherein the controller is configured to control rotation speed of the drum such that the laundry moves in the predetermined motion, based on the signal and the other signal. 
 
     
     
       6. The washing machine of  claim 5 , wherein the laundry detection sensor and the other laundry detection sensor are configured to emit at least one of infrared rays, laser, radio waves, ultrasounds, and acoustic waves to the inside of the drum, and receive at least one of infrared rays, laser, radio waves, ultrasounds, and acoustic waves reflected from the laundry, and the controller is configured to determine a motion of the laundry based on at least one of infrared rays, laser, radio waves, ultrasounds, and acoustic waves received by the laundry detection sensor and the other laundry detection sensor. 
     
     
       7. The washing machine of  claim 6 , wherein the controller is configured to control rotation speed of the drum based on a first detection time for which the laundry detection sensor receives at least one of the infrared rays, laser, radio waves, ultrasounds, and acoustic waves and a second detection time for which the other laundry detection sensor receives at least one of the infrared rays, laser, radio waves, ultrasounds, and acoustic waves. 
     
     
       8. The washing machine of  claim 7 , wherein the controller is configured to control rotation speed of the drum based on a ratio of the first detection time and the second detection time. 
     
     
       9. The washing machine of  claim 1 , wherein the controller is configured to change rotation speed of the drum such that the laundry moves in at least two different motions during a washing course. 
     
     
       10. The washing machine of  claim 9 , wherein the controller is configured to change rotation speed of the drum such that the laundry moves in different motions depending on a quantity of the laundry. 
     
     
       11. The washing machine of  claim 9 , wherein the controller is configured to change rotation speed of the drum such that the laundry moves in different motions depending on materials of the laundry. 
     
     
       12. The washing machine of  claim 1 , wherein the controller is configured to control rotation speed of the drum such that the laundry is rotated along with the drum while being pushed close to an inner circumferential face of the drum during a rinsing course. 
     
     
       13. The washing machine of  claim 12 , further comprising a water supplier configured to supply water to the drum,
 wherein the controller is configured to control the water supplier to supply water to the drum while rotation speed of the drum is being reduced. 
 
     
     
       14. The washing machine of  claim 12 , further comprising a drain part configured to drain water contained in the drum,
 wherein the controller is configured to control the drain part to drain water contained in the drum while rotation speed of the drum is being increased. 
 
     
     
       15. A method for controlling a washing machine including a cabinet on which an opening is formed and a door arranged to close the opening, the method comprising:
 rotating a drum, which is rotationally arranged in the cabinet to contain laundry; 
 detecting, by a laundry detection sensor, a motion of the laundry, wherein the laundry detection sensor is installed in an upper part of the door; and 
 controlling rotation speed of the drum based on the detected motion such that the laundry moves in a predetermined motion. 
 
     
     
       16. The method of  claim 15 , wherein the detecting of the motion of the laundry comprises:
 emitting at least one of infrared rays, laser, radio waves, ultrasound, and acoustic waves to the inside of the drum; 
 receiving at least one of infrared rays, laser, radio waves, ultrasound, and acoustic waves reflected from the laundry; and 
 determining a motion of the laundry based on a reception time for at least one of the received infrared rays, laser, radio waves, ultrasound, and acoustic waves. 
 
     
     
       17. The method of  claim 15 , wherein the controlling of the rotation speed of the drum comprises changing rotation speed of the drum such that the laundry moves in at least two different motions. 
     
     
       18. The method of  claim 17 , wherein the controlling of the rotation speed of the drum comprises changing rotation speed of the drum such that the laundry moves in different motions depending on a quantity of the laundry. 
     
     
       19. The method of  claim 17 , wherein the controlling of the rotation speed of the drum comprises changing rotation speed of the drum such that the laundry moves in different motions depending on materials of the laundry. 
     
     
       20. The method of  claim 16 , wherein the controlling of the rotation speed of the drum comprises controlling rotation speed of the drum such that the laundry is rotated along with the drum while being pushed close to an inner circumferential face of the drum during a rinsing course.